The present invention is directed to related apparatus systems, equipment and methods for entering cavities of the body.
The current trend in medicine is to perform less invasive procedures so as to minimize the trauma to the patient and shorten the recovery period. A major emphasis is to make as few incisions and as small of an incision as is possible to gain access to the interior of the patient. One area of medicine in which these techniques are being used more frequently is in heart surgery. Open heart surgery typically requires significant hospitalization and recuperation time for the patient. While very effective in many cases, the use of open heart surgery to perform various surgical procedures such as coronary artery bypass grafting (CABG) is highly traumatic to the patient. In addition, open heart procedures require the use of cardiopulmonary bypass (CPB) which continues to represent a major assault on a host of body systems.
The CABG procedure generally involves open chest surgical techniques to patient is cut in order to spread the chest apart and provide access to the heart. During surgery the heart is stopped, and by the use of CPB blood is diverted from the lungs to an artificial oxygenator. In general, a source of arterial blood is then connected to a coronary artery downstream from the occlusion. The source of blood is often an internal artery, and the target coronary artery is typically among the anterior or posterior arteries which may be narrowed or occluded.
Multiple incisions have to be made in the arteries to accomplish the diversion of the blood. The leading cause of morbidity and disability following cardiac surgery is cerebral complications. At each incision, there is a risk of gaseous and solid micro and macro emboli, and less often perioperative cerebral hypoperfusion, which produce neurologic effects ranging from subtle neuropsychologic deficits to fatal stroke. Therefore, there is a need to minimize the number and size of incisions.
Open heart surgery is just one area of medicine, that would benefit from less invasive apparatus and procedures, others include dialysis and laparoscopic surgery just to name a couple.
Two obstacles to performing surgery is the number of incisions that must be made in various arteries, vessels, ventricles, atriums and cavity walls of the patient and the safe insertion and withdrawal of various devices and elements through those incisions.
One application for cannulas involves the augmenting or supplementation of pulmonary blood flow through the beating heart during heart surgery by use of one or more cannulas involved in the intake and return of blood into the circulatory system. The cannulas interface between the patient""s circulatory system and the mechanical pumps that power the argumentation procedure.
When performing cardiac surgery cannulas are placed within the patient""s blood stream and used for inflow and outflow of blood or other fluids. One such bypass circuit would be a cardiopulmonary bypass circuit (CPB), in which an outflow cannula is placed in the patient""s right atrium and a return cannula is placed in the aorta. The outflow cannula can be further connected to an oxygenator, blood filter, or blood heater. Even though there are negative side effects of using on pump bypasses, doctors continue to do so because of the ease and reliability of establishing the circuit.
Though presently there is a movement away from stopped heart CPB to beating heart surgery. The movement to beating heart surgery is hampered by common bypass techniques and equipment. One such problem occurs while performing a coronary artery bypass graft (CABG) on the back side of the heart. In order to access vessels on the back side of the heart the surgeon must rotate the heart. Though rotating the heart while the heart is still beating raises new complications that were not present during stopped heart surgery. Many times rotating the beating heart leads to further complications such as a decrease in pulmonary pressure which results in a decrease in oxygen content in the patient""s blood. Thus many times when a surgeon is performing a graft on the back side of the heart, the heart must be rotated and replaced many times to stabilize the patient""s blood pressure.
The present invention provides cannula devices which can be inserted through an incision in a body cavity to allow ingress and egress in separate cannulas simultaneously through the incision with minimal trauma.
One aspect of the present invention provides a cannula device which has at least two openings at least one of which initially is concealed or closed but which after being inserted through the wall of a cavity (for example, the aorta) can be opened to allow ingress and egress through the two openings simultaneously through the incision in the wall of the cavity. One embodiment provides a cannulation device for access to an interior body region comprises a cannula body having a distal end for insertion through an incision and including first and second interior flow paths to circulate fluid. A conduit communicates with one of the first and second flow paths and extends beyond the distal end of the cannula body to input or outflow fluid at an area of the interior body region spaced from the distal end. A port communicates with the other one of the first and second flow paths to input or outflow fluid at the distal end. A closure assembly on the cannula body operates in a first condition to close the port, thereby preventing fluid circulation within the cannula body between the first and second flow paths. The closure assembly operates in a second condition to open the port, thereby allowing fluid circulation within the cannula body between the first and second flow paths.
Another aspect of the invention provides a system for circulating blood in a heart. The system comprises a cannula body having a distal end for insertion through an incision and including first and second interior flow paths to circulate blood. A conduit communicates with one of the first and second flow paths. The conduit is sized to extend, in use, beyond the distal end of the cannula body for passage into a heart chamber, to thereby input or outflow blood from the heart chamber. The conduit includes a performed, bent region to direct its passage from the distal end into the heart chamber. A port communicates with the other one of the first and second flow paths to input or outflow blood at the distal end.
Another aspect of the invention provides a cannula for access to an interior body region comprising a body defining a lumen having a distal region. The lumen includes a two dimensional configuration, e.g., one or more bends, in the distal region to aid placement of the cannula in the interior body region.
Any aspect of the invention is usable in association with a pump, which operates, in use, to intake fluid and output fluid.